28eb5f274a
After commit 852972acff (ACPI: Disable
ASPM if the platform won't provide _OSC control for PCIe) control of
the PCIe Capability Structure is unconditionally requested by
acpi_pci_root_add(), which in principle may cause problems to
happen in two ways. First, the BIOS may refuse to give control of
the PCIe Capability Structure if it is not asked for any of the
_OSC features depending on it at the same time. Second, the BIOS may
assume that control of the _OSC features depending on the PCIe
Capability Structure will be requested in the future and may behave
incorrectly if that doesn't happen. For this reason, control of
the PCIe Capability Structure should always be requested along with
control of any other _OSC features that may depend on it (ie. PCIe
native PME, PCIe native hot-plug, PCIe AER).
Rework the PCIe port driver so that (1) it checks which native PCIe
port services can be enabled, according to the BIOS, and (2) it
requests control of all these services simultaneously. In
particular, this causes pcie_portdrv_probe() to fail if the BIOS
refuses to grant control of the PCIe Capability Structure, which
means that no native PCIe port services can be enabled for the PCIe
Root Complex the given port belongs to. If that happens, ASPM is
disabled to avoid problems with mishandling it by the part of the
PCIe hierarchy for which control of the PCIe Capability Structure
has not been received.
Make it possible to override this behavior using 'pcie_ports=native'
(use the PCIe native services regardless of the BIOS response to the
control request), or 'pcie_ports=compat' (do not use the PCIe native
services at all).
Accordingly, rework the existing PCIe port service drivers so that
they don't request control of the services directly.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
138 lines
4.1 KiB
C
138 lines
4.1 KiB
C
/*
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* ACPI related functions for PCI Express Hot Plug driver.
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*
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* Copyright (C) 2008 Kenji Kaneshige
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* Copyright (C) 2008 Fujitsu Limited.
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*
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for more
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* details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <linux/acpi.h>
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#include <linux/pci.h>
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#include <linux/pci_hotplug.h>
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#include <linux/slab.h>
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#include "pciehp.h"
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#define PCIEHP_DETECT_PCIE (0)
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#define PCIEHP_DETECT_ACPI (1)
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#define PCIEHP_DETECT_AUTO (2)
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#define PCIEHP_DETECT_DEFAULT PCIEHP_DETECT_AUTO
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struct dummy_slot {
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u32 number;
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struct list_head list;
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};
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static int slot_detection_mode;
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static char *pciehp_detect_mode;
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module_param(pciehp_detect_mode, charp, 0444);
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MODULE_PARM_DESC(pciehp_detect_mode,
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"Slot detection mode: pcie, acpi, auto\n"
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" pcie - Use PCIe based slot detection\n"
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" acpi - Use ACPI for slot detection\n"
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" auto(default) - Auto select mode. Use acpi option if duplicate\n"
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" slot ids are found. Otherwise, use pcie option\n");
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int pciehp_acpi_slot_detection_check(struct pci_dev *dev)
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{
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if (slot_detection_mode != PCIEHP_DETECT_ACPI)
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return 0;
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if (acpi_pci_detect_ejectable(DEVICE_ACPI_HANDLE(&dev->dev)))
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return 0;
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return -ENODEV;
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}
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static int __init parse_detect_mode(void)
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{
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if (!pciehp_detect_mode)
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return PCIEHP_DETECT_DEFAULT;
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if (!strcmp(pciehp_detect_mode, "pcie"))
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return PCIEHP_DETECT_PCIE;
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if (!strcmp(pciehp_detect_mode, "acpi"))
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return PCIEHP_DETECT_ACPI;
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if (!strcmp(pciehp_detect_mode, "auto"))
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return PCIEHP_DETECT_AUTO;
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warn("bad specifier '%s' for pciehp_detect_mode. Use default\n",
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pciehp_detect_mode);
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return PCIEHP_DETECT_DEFAULT;
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}
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static int __initdata dup_slot_id;
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static int __initdata acpi_slot_detected;
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static struct list_head __initdata dummy_slots = LIST_HEAD_INIT(dummy_slots);
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/* Dummy driver for dumplicate name detection */
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static int __init dummy_probe(struct pcie_device *dev)
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{
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int pos;
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u32 slot_cap;
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acpi_handle handle;
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struct dummy_slot *slot, *tmp;
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struct pci_dev *pdev = dev->port;
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pos = pci_pcie_cap(pdev);
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if (!pos)
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return -ENODEV;
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pci_read_config_dword(pdev, pos + PCI_EXP_SLTCAP, &slot_cap);
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slot = kzalloc(sizeof(*slot), GFP_KERNEL);
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if (!slot)
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return -ENOMEM;
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slot->number = slot_cap >> 19;
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list_for_each_entry(tmp, &dummy_slots, list) {
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if (tmp->number == slot->number)
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dup_slot_id++;
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}
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list_add_tail(&slot->list, &dummy_slots);
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handle = DEVICE_ACPI_HANDLE(&pdev->dev);
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if (!acpi_slot_detected && acpi_pci_detect_ejectable(handle))
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acpi_slot_detected = 1;
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return -ENODEV; /* dummy driver always returns error */
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}
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static struct pcie_port_service_driver __initdata dummy_driver = {
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.name = "pciehp_dummy",
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.port_type = PCIE_ANY_PORT,
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.service = PCIE_PORT_SERVICE_HP,
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.probe = dummy_probe,
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};
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static int __init select_detection_mode(void)
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{
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struct dummy_slot *slot, *tmp;
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pcie_port_service_register(&dummy_driver);
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pcie_port_service_unregister(&dummy_driver);
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list_for_each_entry_safe(slot, tmp, &dummy_slots, list) {
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list_del(&slot->list);
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kfree(slot);
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}
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if (acpi_slot_detected && dup_slot_id)
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return PCIEHP_DETECT_ACPI;
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return PCIEHP_DETECT_PCIE;
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}
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void __init pciehp_acpi_slot_detection_init(void)
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{
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slot_detection_mode = parse_detect_mode();
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if (slot_detection_mode != PCIEHP_DETECT_AUTO)
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goto out;
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slot_detection_mode = select_detection_mode();
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out:
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if (slot_detection_mode == PCIEHP_DETECT_ACPI)
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info("Using ACPI for slot detection.\n");
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}
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